package com.bwt.algorithm.binarySearchNoRecursion;

public class BinarySearchNoRecursion {
    public static void main(String[] args) {
        int[] arr = {1, 3, 8, 10, 11,67,100};
        int index = binarySearch(arr, 1);
        System.out.println(arr[index]);
    }

    /**
     * 二分查找的非递归实现
     * @param arr 待查找的数组, arr是升序排列
     * @param target 需要查找的树
     * @return 返回对应的下标 -1 表示未找到
     */
    public static int binarySearch(int[] arr, int target) {
        int left = 0;
        int right = arr.length - 1;
        while (left <= right) {//说明可以继续查找
            int mid = (left + right) / 2;
            if (arr[mid] == target) {
                return mid;
            } else if (arr[mid] > target) {
                right = mid - 1;// 需要向左边查找
            } else {
                left = mid + 1;
            }
        }
        return -1;
    }
}
